Laboratory of Neurophysiology, Korea Brain Research Institute, Daegu 41062, Korea.
Department of Brain & Cognitive Sciences, Daegu Gyeongbuk Institute of Science & Technology, Daegu 42988, Korea.
Mol Cells. 2022 Feb 28;45(2):84-92. doi: 10.14348/molcells.2022.2021.
To understand the microcircuitry of the brain, the anatomical and functional connectivity among neurons must be resolved. One of the technical hurdles to achieving this goal is that the anatomical connections, or synapses, are often smaller than the diffraction limit of light and thus are difficult to resolve by conventional microscopy, while the microcircuitry of the brain is on the scale of 1 mm or larger. To date, the gold standard method for microcircuit reconstruction has been electron microscopy (EM). However, despite its rapid development, EM has clear shortcomings as a method for microcircuit reconstruction. The greatest weakness of this method is arguably its incompatibility with functional and molecular analysis. Fluorescence microscopy, on the other hand, is readily compatible with numerous physiological and molecular analyses. We believe that recent advances in various fluorescence microscopy techniques offer a new possibility for reliable synapse detection in large volumes of neural circuits. In this minireview, we summarize recent advances in fluorescence-based microcircuit reconstruction. In the same vein as these studies, we introduce our recent efforts to analyze the long-range connectivity among brain areas and the subcellular distribution of synapses of interest in relatively large volumes of cortical tissue with array tomography and superresolution microscopy.
为了理解大脑的微电路，必须解析神经元之间的解剖学和功能连接。实现这一目标的技术障碍之一是，解剖学连接（即突触）通常小于光的衍射极限，因此难以通过传统显微镜来解析，而大脑的微电路则处于 1 毫米或更大的尺度上。迄今为止，微电路重建的金标准方法是电子显微镜（EM）。然而，尽管 EM 迅速发展，但它作为微电路重建的方法仍存在明显的缺点。这种方法最大的弱点可以说是它与功能和分子分析不兼容。另一方面，荧光显微镜与许多生理和分子分析都很容易兼容。我们认为，各种荧光显微镜技术的最新进展为在大量神经回路中可靠地检测突触提供了新的可能性。在这篇简评中，我们总结了基于荧光的微电路重建的最新进展。与这些研究一样，我们介绍了我们最近使用阵列断层扫描和超分辨率显微镜在相对较大的皮质组织体积中分析脑区之间的远程连接以及感兴趣的突触的亚细胞分布的努力。
